If I was to hazard a guess, based on the ending to the last game, I -think- they might be going back to the more orthodox large army command for the next game. It's just a guess, but the last game ended with your commander character promoted to lead his own company and assorted armies poised to enter the battle for the system once again on a grander scale. I was half expecting a sort of open map based kind of approach as they adopted for the later iterations of the older Dawn of War. Not sure if Orks would work as well as Space Marines for a campaign along the lines of the original Dawn of War 2 because while I can imagine a small unit of Space Marines with veteran squad leaders battling huge odds and so on, I imagine orks having a much higher attrition rate, plus they tend to mob things.